Showing papers on "Solid-state fermentation published in 2005"
TL;DR: The relevance of applying SSF technology in the production of mycotoxins, biofuels, and biocontrol agents is discussed, and the need for adopting SSFtechnology in bioremediation of toxic compounds, biological detoxication of agro-industrial residues, andBiotransformation of agri-products and residues is emphasized.
Abstract: Starting with a brief history of solid-state fermentation (SSF), major aspects of SSF are reviewed, which include factors affecting SSF, biomass, fermentors, modeling, industrial microbial enzymes, organic acids, secondary metabolites, and bioremediation. Physico-chemical and environmental factors such as inoculum type, moisture and water activity, pH, temperature, substrate, particle size, aeration and agitation, nutritional factors, and oxygen and carbon dioxide affecting SSF are reviewed. The advantages of SSF over Submerged Fermentation (SmF) are indicated, and the different types of fermentors used in SSF described. The economic feasibilities of adopting SSF technology in the commercial production of industrial enzymes such as amylases, cellulases, xylanase, proteases, phytases, lipases, etc., organic acids such as citric acid and lactic acid, and secondary metabolites such as gibberellic acid, ergot alkaloids, and antibiotics such as penicillin, cyclosporin, cephamycin and tetracyclines are highlighted. The relevance of applying SSF technology in the production of mycotoxins, biofuels, and biocontrol agents is discussed, and the need for adopting SSF technology in bioremediation of toxic compounds, biological detoxication of agro-industrial residues, and biotransformation of agro-products and residues is emphasized.
617 citations
TL;DR: In this article, a comparative study was carried out on the production of neutral protease using agro-industrial residues as substrate in solid-state fermentation (SSF) and submerged fermentation (SmF).
355 citations
TL;DR: In this paper, the authors present a review of the production of ligninolytic enzymes by Solid State Fermentation (SSF) technique, which has become an attractive alternative to submerged fermentation (SmF) for specific applications due to the recent improvements in reactor designs.
248 citations
TL;DR: Bacillus sp. PS-7, isolated from the hot springs of Manikaran (H.P.), India, produced very high levels of thermostable α-amylase by solid state fermentation (SSF) in Erlenmeyer flasks and enamel coated metallic trays as discussed by the authors.
207 citations
TL;DR: The production of extracellular amylase by the thermophilic fungus Thermomyces lanuginosus was studied in solid state fermentation (SSF) and growth on wheat bran gave the highest amyl enzyme activity.
200 citations
TL;DR: The nitrogen sources peptone, yeast extract and tri-ammonium citrate, along with NaH2PO4.2H2O and Tween 80, were found to influence productivity, which can be further optimized for increased lactic acid production.
178 citations
TL;DR: Results from the study are promising for the economic utilization and value addition of these important agro residues, which are abundantly available in many tropical and subtropical countries.
172 citations
TL;DR: The enzymes analyses demonstrated that grape pomace could be competitive with other typical agroindustrial wastes used as substrates in SSF processes.
164 citations
TL;DR: The level of protease activity was considerably decreased in optimized medium, thus helping to preserve the xylanase activity and demonstrating another advantage of applying statistical experimental design.
163 citations
TL;DR: In this paper, the authors studied the production of CMCase and xylanase by a Brazilian strain of Thermoascus aurantiacus in solid state fermentation (SSF) using different agricultural residues (wheat bran, sugarcane bagasse, orange bagasse and corn straw) as substrates without enrichment of the medium and characterized the crude enzymes.
160 citations
TL;DR: In this article, solid-state fermentation of a mixture of orange bagasse and wheat bran with the filamentous fungus Penicillium viridicatum RFC3 was investigated.
TL;DR: In this paper, the authors used three strains of Rhizopus spp. namely, Rhizope oligosporus NRRL 5905, rhizopus oryzae NRRL 1891 and R. oryzaa NRRL 3562 to produce phytase in mixed substrate fermentation.
TL;DR: In this article, the ability of Lactobacillus amylophilus GV6 to hydrolyze raw starch in wheat bran to produce l (+) lactic acid was studied in solid state fermentation (SSF), opening a novel method for the utilization of these agricultural byproducts.
TL;DR: In this article, Aspergillus flavipes BICC 5174 was used for the production of lovastatin by solid state fermentation (SSF) using different solid substrates such as wheat bran, bagasse, barley, soybean meal, gram bran and fruits waste and some of their combinations were tested for Lovastatin production.
TL;DR: This paper reports the production of very high levels of cellulase free xylanase and associated hemicellulases by an indigenous thermophilic isolate of Thermomyces lanuginosus using solid-state fermentation.
TL;DR: Very low levels of cellulolytic enzyme activities were observed compared to lignin degrading enzymes by both the organisms.
TL;DR: Yeast extract, beef extract and xylan enhanced enzyme production, while glucose, lactose and fructose strongly repressed the production process.
TL;DR: A locally isolated strain of Aspergillus foetidus MTCC 4898 was studied for xylanase production using lignocellulosic substrates under solid state fermentation, and corncobs were found as the best substrates for high yield of xylanases with poor cellulase production.
Abstract: A locally isolated strain of Aspergillus foetidus MTCC 4898 was studied for xylanase (EC 3.2.1.8) production using lignocellulosic substrates under solid state fermentation. Corncobs were found as the best substrates for high yield of xylanases with poor cellulase production. The influence of various parameters such as temperature, pH, moistening agents, moisture level, nitrogen sources and pretreatment of substrates were evaluated with respect to xylanase yield, specific activity and cellulase production. Influence of nitrogen sources on protease secretion was also examined. Maximum xylanase production (3065 U/g) was obtained on untreated corncobs moistened with modified Mandels and Strenberg medium, pH 5.0 at 1 5 moisture levels at 30 °C in 4 days of cultivation. Submerged fermentation under the same conditions gave higher yield (3300 U/g) in 5 days of cultivation, but productivity was less. Ammonium sulphate fractionation yielded 3.56-fold purified xylanase with 76% recovery. Optimum pH and temperature for xylanase activity were found to be 5.3 and 50 °C respectively. Kinetic parameters like K
m
and V
max
were found to be 3.58 mg/ml and 570 μmol/mg/min. Activity of the enzyme was found to be enhanced by cystiene hydrochloride, CoCl2, xylose and Tween 80, while significantly inhibited by Hg++, Cu++ and glucose. The enzyme was found to be stable at 40 °C. The half life at 50 °C was 57.53 min. However thermostability was enhanced by glycerol, trehalose and Ca++. The crude enzyme was stable during lyophilization and could be stored at less than 0 °C.
TL;DR: The production of lipase by Penicillium simplicissimum in solid-state fermentation was studied using babassu cake as the basal medium and Tray-type and packed-bed bioreactors were employed.
Abstract: The production of lipase by Penicillium simplicissimum in solid-state fermentation was studied using babassu cake as the basal medium. Tray-type and packed-bed bioreactors were employed. In the former, the influence of temperature; content of the medium, and medium supplementation with olive oil, sugarcane molasses, corn steep liquor, and yeast hydrolysate was studied. For all combinations of supplements, a temperature of 30 degrees C, a moisture content of 70%, and a concentration of carbon source of 6.25% (m/m, dry basis) provided optimum conditions for lipase production. When used as single supplements olive oil and molasses also were able to provide high lipase activities (20 U/g). Using packed-bed bioreactors and molasses-supplemented medium, optimum conditions for enzyme production were air superficial velocities above 55 cm/min and temperatures below 28 degrees C. The lower temperature optimum found for these reactors is probably related to radial heat gradient formation inside the packed bed. Maximum lipase activities obtained in these bioreactors (26.4 U/g) were 30% higher than in tray-type reactors.
Journal Article•
TL;DR: Five strains of fungi belonging to Aspergillus sp.
Abstract: Summary Five strains of fungi belonging to Aspergillus sp. were evaluated by casein agar plate assay and a wheat bran-based solid-state fermentation for selecting a neutral protease-producing culture. Based on the results, A. oryzae NRRL 2217 was selected for further studies. Sixteen different agro-industrial residues were evaluated for their potential to serve as a substrate for neutral protease production by this fungal strain. Results showed that a combination of coconut oil cake and wheat bran in the mass ratio of 1:3 was the best substrate for enzyme production. Various process parameters influencing protease production including fermentation time, initial moisture content, and fermentation temperature were optimised. The medium was supplemented with different nutrients in the form of organic and inorganic nitrogen and carbon sources. Supplementation of chitin increased the enzyme production significantly. Ammonium nitrate as inorganic nitrogen supplement slightly enhanced enzyme production. No organic nitrogen supplement was effective enhancer of enzyme production. Fermentation was performed under optimised conditions (initial moisture content V/m = 50 %, temperature 30 °C, 48 h). Partial purification of the enzyme resulted in a 3-fold increase in the specific activity of the enzyme. The partially purified enzyme was characterised by various features that govern the enzyme activity such as assay temperature, assay pH and substrate concentration. The effect of various metal ions and known protease inhibitors on the enzyme activity was also studied. The enzyme was found to be stable in pH range 7.0–7.5, and at temperature of 50 °C for 35 min. By the activating effect of divalent cations (Mg 2+ ,C a 2+ ,F e 2+ ) and inhibiting effect of certain chelating agents (EGTA, EDTA), the enzyme was found to be a metalloprotease.
TL;DR: This paper deals with the influence of environmental parameters such as airflow rate, temperature, pH, substrate concentration and other physico-chemical parameters on the production of specific metabolites inSolid-state fermentation.
Abstract: Solid-state fermentation (SSF) involves the growth of microorganisms on moist solid substrates in the absence of free water This low moisture content makes the SSF different from submerged fermentation Unlike the situation in submerged fermentation there is no systematic study guiding the design and operation of large scale SSF with proper controls The understanding and modeling of microbial growth kinetics and transport phenomena play important roles in the SSF The design of bioreactors from tray type to stirred tank is discussed The packed bed, rotating drum, rocking drum, fluidized bed and stirred tank reactors are used in SSF with and without modifications The parameters like pH, temperature, agitation and aeration also need to be controlled There is a large gradient of temperature throughout the trays By manipulating the nitrogen source requirement, the pH of the system is generally controlled The different factors that control the agitation and aeration in the SSF are discussed Finally the advantages and disadvantages of SSF compared to submerged fermentation were mentioned Moreover, such understanding is very much required in the design, scale up and process control in SSF This paper deals with the influence of environmental parameters such as airflow rate, temperature, pH, substrate concentration and other physico-chemical parameters on the production of specific metabolites
TL;DR: The purified chitinase inhibited hyphal extension of Fusarium moniliforme, Aspergillus niger, Mucor rouxi and Rhizopus nigricans, and was effective in release of protoplasts from Trichoderma ressei, Pleurotus florida, Agaricus bisporus and Aspergell niger.
Abstract: In this study flake chitin, crab shell chitin, mushroom stalk, fungal cell wall, wheat bran and rice bran were used as substrate for chitinase production by Enterobacter sp. NRG4 under submerged and solid state fermentation (SSF) conditions. Enterobacter sp. NRG4 produced 72 and 49.7 U/ml of chitinase in presence of cell walls of Candida albicans and Fusarium moniliforme in submerged fermentation. Under SSF, maximum chitinase production was 965 U/g solid substrate with flake chitin and wheat bran (1:3 ratio) at 75% moisture level after 144 h. The purified chitinase inhibited hyphal extension of Fusarium moniliforme, Aspergillus niger, Mucor rouxi and Rhizopus nigricans. The chitinase was effective in release of protoplasts from Trichoderma ressei, Pleurotus florida, Agaricus bisporus and Aspergillus niger. Protoplasts yield was maximum with 60 mg of 24 h old fungal mycelium incubated with 60 U of chitinase and 60 U of cellulase.
TL;DR: Lactobacillus casei was grown on sugarcane bagasse soaked with cassava starch hydrolysate and the maximum yield of l-lactic acid after various process optimisations was 2.9 g/5 g initial substrate corresponding to 97% conversion of sugar to lactic acid with initial substrate moisture of 72%.
Abstract: Lactobacillus casei was grown at 37 degrees C on sugarcane bagasse (5 g) soaked with cassava starch hydrolysate (final moistening volume 34 ml) containing 3 g reducing sugar in a solid-state condition. The maximum yield of L-lactic acid after various process optimisations was 2.9 g/5 g initial substrate corresponding to 97% conversion of sugar to lactic acid with initial substrate moisture of 72%.
TL;DR: Alkaline protease production using isolated Bacillus circulans under solid‐state fermentation environment was optimized by using Taguchi orthogonal array (OA) experimental design (DOE) methodology to understand the interaction of a large number of variables spanned by factors and their settings with a small number of experiments in order to economize the process optimization.
Abstract: Alkaline protease production using isolated Bacillus circulans under solid-state fermentation environment was optimized by using Taguchi orthogonal array (OA) experimental design (DOE) methodology to understand the interaction of a large number of variables spanned by factors and their settings with a small number of experiments in order to economize the process optimization. The software-designed experiments with an OA worksheet of L-27 was selected to optimize fermentation (temperature, particle size, moisture content and pH), nutrition (yeast extract and maltose), and biomaterial-related (inoculum size and incubation time) factors for the best production yields. Analysis of experimental data using Qualitek-4 methodology showed significant variation in enzyme production levels (32,000-73,000 units per gram material) and dependence on the selected factors and their assigned levels. Validation of experimental results on alkaline protease production by this bacterial strain based on DOE methodology revealed 51% enhanced protease production compared to average performance of the fermentation, indicating the importance of this methodology in the evaluation of main and interaction effects of the selected factors individually and in combination for bioprocess optimization.
TL;DR: Under the experimental conditions tested, Penicillium aculeatum NRRL 2129 (=ATCC 10409) was selected as the best enzyme producer and showed optimal temperature and pH at 50 and 5.5 °C, respectively.
TL;DR: Packed bed bioreactors were employed with the aim of increasing productivity and scaling up of lipase production using Penicillium simplicissimum in solid-state fermentation and showed that higher lipase activities could be achieved at lower temperatures and higher air flow rates.
Abstract: In the present work, packed bed bioreactors were employed with the aim of increasing productivity and scaling up of lipase production using Penicillium simplicissimum in solid-state fermentation. The influence of temperature and air flow rate on enzyme production was evaluated employing statistical experimental design, and an empirical model was adjusted to the experimental data. It was shown that higher lipase activities could be achieved at lower temperatures and higher air flow rates. The maximum lipase activity (26.4 U/g) was obtained at the temperature of 27°C and air flow rate of 0.8 L/min.
TL;DR: Solid-state fermentations were carried out for high yield of poly-gamma-glutamic acid (Gamma-PGA) by Bacillus subtilis CCTCC202048 to lay a foundation for lessening the pollution of swine manure, increasing fertilizer efficiency and exploring a late-model organic fertilizer that retains water and nutrients.
TL;DR: The effects of a low oxygen concentration on growth at the levels of individual hyphae, colonies and overcultures, and on alpha-amylase production in overculture are described and the kinetics of growth of A. oryzae are simplified to zero-order kinetics in coupled diffusion/reaction models.
TL;DR: Results indicate that this bacterial strain shows a high biotechnological potential for protease production in solid-state fermentations (SSF) using soy cake as culture medium.
Abstract: A Bacillus subtilis isolate was shown to be able to produce extracellular protease in solid-state fermentations (SSF) using soy cake as culture medium. A significant effect of inoculum concentration and physiological age on protease production was observed. Maximum activities were obtained for inoc-ula consisting of exponentially growing cells at inoculum concentrations in the range of 0.7–2.0 mg g−1. A comparative study on the influence of cultivation temperature and initial medium pH on protease production in SSF and in submerged fermentation (SF) revealed that in SSF a broader pH range (5–10), but the same optimum temperature (37°C), is obtained when compared to SF. A kinetic study showed that enzyme production is associated with bacterial growth and that enzyme inactivation begins before biomass reaches a maximum level for both SF and SSF. Maximum protease activity and productivity were 960 U g−1 and 15.4 U g−1 h−1 for SSF, and 12 U mL−1 and 1.3 U mL−1 h−1 for SF. When SSF protease activity was expressed by volume of enzyme extract, the enzyme level was 10-fold higher and the enzyme productivity 45% higher than in SF. These results indicate that this bacterial strain shows a high biotechnological potential for protease production in solid-state fermentation.
TL;DR: The respirometric analyses of the fermentation showed a strong correlation between fungal growth and spore production and Beauveria bassiana by Solid-State Fermentation.
Abstract: The purpose of this work was to produce Beauveria bassiana by Solid-State Fermentation using agro-industrial residues and optimizing the cultivation conditions. Refused potatoes, coffee husks and sugar-cane bagasse were tested. The blend of refused potatoes and sugar-cane bagasse (60-40%) with particle size in the range of 0.8-2 mm was used in the fermentation experiments. In Erlenmeyer flasks the best spore production was achieved with the following conditions: incubation temperature 26o C; initial pH 6.0; inoculum concentration 107 spores.g-1.dw and initial moisture 75%. In the column type reactor using forced aeration under the optimized conditions, the maximum production (1.07x1010spores.g-1.dw) was obtained at the 10th day of fermentation. The respirometric analyses of the fermentation showed a strong correlation between fungal growth and spore production.